/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.runners.fnexecution.state;



import com.bff.gaia.unified.model.fnexecution.v1.UnifiedFnApi.StateRequest;



/**

 * The {@link StateDelegator} is able to delegate {@link StateRequest}s to a set of registered

 * handlers. Any request for an unregistered process bundle instruction id is automatically failed.

 */

public interface StateDelegator {

  /**

   * Registers the supplied handler for the given process bundle instruction id for all {@link

   * StateRequest}s with a matching id. A handle is returned which allows one to deregister from

   * this {@link StateDelegator}.

   */

  Registration registerForProcessBundleInstructionId(

	  String processBundleInstructionId, StateRequestHandler handler);



  /** Allows callers to deregister from receiving further state requests. */

  interface Registration {

    /**

     * De-registers the handler for all future requests for state for the registered process bundle

     * instruction id.

     */

    void deregister();



    /**

     * De-registers the handler for all future requests for state for the registered process bundle

     * instruction id. Aborts all in-flight state requests.

     */

    void abort();

  }

}